Pop-up targets are used in law enforcement and military training to improve the ability of shooters to hit a target in a desired location. Because pop-up targets are very light and flimsy to insure fast response, the whole structure vibrates violently whenever a bullet punctures its surface so that determining the hit point is not practical.
Determination of hit point on a pop-up target is difficult if not impossible in many instances with current sensing techniques. When hit by ballistics, target vibrations set up their own characteristic waveforms associated with the target itself rather than producing characteristic vibrations associated with a bullet passing through the plastic material of the target. The target twists and turns during the impact in a similar manner no matter where the bullet might hit.
Use of supersonic sound sensors allows accurate aim-point to be determined. However, if the projectile is not supersonic there is a problem. For indoor use, placement of shock sensors all over a target can be used, however, in a live fire range, damage to the sensors may be a considerable problem.